#lang rosetta-racket


(require "sphere-of-cones.rkt")

(provide pierced-sphere)


(define (pierced-sphere r e rc n)
  (let ((hollow-sphere (subtract (sphere r) (sphere (- r e))))
        (cones (sphere-of-cones rc (* 1.1 r) n)))
    (for ((cone cones))
      (set! hollow-sphere (subtract hollow-sphere cone)))
    hollow-sphere))